Communications systems depend on various protocols for transmitting signals from a transmitter to a receiver. Some protocols reflect physical layer of communications. When signals are transmitted on the physical layer, spreading sequences may be used to overcome noise that may exist on the signal. Specifically, each bit in the signal is encoded with a predefined series of bits. The number of bits in the series is specified by a spreading factor. For example, a zero (0) may be encoded with a predefined series of bits having a length defined by the spreading factor. Conversely, a one (1) may be encoded with a different predefined series of bits having a length defined by the spreading factor.
It is desired to generate spreading sequences that is useful for energy efficient ultra-low power communication. Non-coherent communication is preferred for the ultra-low power communication over short ranges. To enable ultra-low power communications, the spreading sequences play a vital role that is used as preambles and for spreading the data. The properties of the spreading sequences impact the energy efficiency of the overall communication system. Also for interoperability and adherence to spectral mask constraints in unlicensed bands; it is attractive that the sequences also be usable in coherent mode communications.
The above information is presented as background information only to help the reader to understand the present invention. Applicants have made no determination and make no assertion as to whether any of the above might be applicable as Prior Art with regard to the present application.